About 15 million root canals are performed each year in the United States. Failure rates are about 10%, with the failed initial treatment reflecting costs in the US of over 900 million dollars per year. While there are a number of causes of the failures, one of the primary causes is the inability to assess the difficulty of the root canal's morphology, i.e., its path in three dimensions (3D). Practitioners acquire multiple radiographs to facilitate a mental estimation of this path. This estimation is limited by the fact that the 3D structures are represented in 2D images, and impairs the ability to mentally reconstruct the full morphology of the canal. 3D root canal morphology will enable improved treatment planning and improve the likelihood of success of the treatment. CT might be an option;however, CT technology is not readily available to the dentists. Because of CT's high cost, patient dose, reduced resolution, equipment size, and relative complexity, it is impractical for most dentists, in particular the general practitioner, to use CT or have such machines in their office. In the proposed research, we will evaluate the feasibility of reconstructing the 3D root canal morphology using only the radiographs that are normally acquired during a root canal procedure. Our proposed technology will provide the same the 3D root canal morphology that was previously available only using CT technology. Moreover, our technology will overcome the issues associated with CT and provide the dentist with a low cost, accurate, and easy to use product that will not require additional dose to the patient and can be run on a standard computer. In addition, we will overcome issues that could limit the quality of the generated 3D, by innovative approaches in which we take advantage of the "completing data" in the other views. To evaluate the product's feasibility, we will (1) Develop technology which allows quick and easy visualization and quantitation of 3D root canal centerlines from standard dental radiographs and allows quantitative assessment of critical structures and overcomes issues of overlap and low SNR (2) Evaluate the accuracy of the technology by comparing its results to those of micro-CT, and (3) Evaluate the impact of the developed technology on root canal procedures. Significance: With our technology, 3D root canals can be available in every dental office, using simply the radiographs they are already acquiring, at a fraction of the cost of CT, with no additional space requirements, and with the ease and speed of a few clicks of the mouse. With our technology, visualization and analysis of 3D root canals could easily become the standard of care improving dental care for millions of patients. PUBLIC HEALTH RELEVANCE: Root canal treatment decisions rely on evaluations of 2D radiographic images and mental reconstructions of the 3D root canal path. We have developed a simple and accurate method for determination of the 3D root canal path from two or more radiographic views. Its low cost, ease of use, accuracy, and clinical impact will drive expansion of 3D as the standard of care in root canal procedures positively impacting treatment decisions and treatment outcome for millions of patients.